Antenna with built-in filter

ABSTRACT

A laminated dielectric block ( 3 ) is formed by laminating dielectric sheets ( 31 ) each having a conductive film formed on its one surface so as to constitute at least one filter ( 2 ). A radiation element ( 1 ) is provided so as to fix to the laminating dielectric block, wherein one electrode of the filter is electrically connected to the radiation element. The other electrode ( 22 ) of the filter is connected to a feeding terminal electrode ( 4 ) provided mounting face B (a face opposing to a circuit board) of the laminated dielectric block through a via-contact ( 33 ) and a wiring ( 34 ), not being exposed to the side face. As a result, an antenna with built-in filter of the structure where even if it is mounted on a circuit board, interference between an electronic circuit on the circuit board and the feeding terminal electrode of the antenna is prevented to improve the isolation characteristic and transmitting or receiving characteristic.

This application is the U.S. National Phase of International AplicationPCT/JP03/08435 filed Jul. 3, 2003 which claims priority of JP2002-196684filed Jul. 5, 2002.

TECHNICAL FIELD

The present invention relates to an antenna with built-in filter that iscompact, easy to get a match and suitable to be mounted to a cellularphone or portable terminal device and has a configuration of not beinginterfered with an electronic circuit on a circuit board when it ismounted on the circuit board. More specifically, the invention relatesto an antenna with built-in filter having a configuration of preventingthat, even in the case where it is used in plural frequency bands suchas for a cellular phone and for a GPS or Bluetooth, for example, theother signal inputs into a receiving circuit side via a feeding terminalelectrode to be interfered with each other.

BACKGROUND ART

An antenna is conventionally configured to be capable of receiving ortransmitting only a signal of a desired frequency band via a filter suchas a band pass filter. Conventionally, the filter individuallymanufactured has been externally connected to an antenna for use.Recently, an antenna with built-in filter wherein an antenna and afilter are integrated has been developed for eliminating a troublesomework of matching an antenna and a filter or for meeting a demand ofdownsizing an electronic device.

As shown by a partially perspective explanatory view and its sectionalexplanatory view of FIGS. 7A and 7B illustrating one example of a statewhere an antenna with built-in filter 85 is mounted on a circuit board86, the antenna with built-in filter 85 as described above has alaminated dielectric block 83 obtained by laminating dielectric sheetshaving a conductive pattern formed thereon for forming a capacitor orinductor that composes a filter and by sintering the resultant. Aradiation element 81 is formed on the front face of the laminateddielectric block 83. One electrode of the filter is electricallyconnected to the radiation element 81, while the other electrode isconnected to a feeding terminal electrode 84 provided at the outer faceof the laminated dielectric block 83 so as to be able to be connected toa transmit-receive circuit that is an external circuit.

As shown in FIG. 7B in which the sectional explanatory view of FIG. 7Ais illustrated, in the conventional antenna with built-in filter of thistype, a wiring film 834 is extended to an end section to be drawn outfrom the other electrode of the filter 82 made of a conductive patternon which an inductor or capacitor is formed, and after forming thelaminated dielectric block 83, the feeding terminal electrode 84 isconnected to the wiring film 834 exposed to its side face, whereby thefeeding terminal electrode 84 is formed so as to go up to the back face(mounting face of the circuit board 86) from its side face. This feedingterminal electrode 84 is directly connected to a feeder 862 of thecircuit board 86 by a soldering.

As described above, in the conventional antenna with built-in filter,the other electrode of the filter is drawn to the side face of thedielectric block 83 and the feeding terminal electrode 84 is providedfrom the side face of the dielectric block 83 to the mounting face (theface opposing to the circuit board on which the antenna is mounted,i.e., back face) so as to be connected to the drawn wiring film 834.Therefore, the case is likely to occur where radio wave received andtransmitted by the radiation element 81 is directly picked up by thefeeding terminal electrode 84 on the side face of the dielectric block.Further, an antenna is recently configured to be capable of receivingand transmitting a signal of two or more frequency bands by a cellularphone, i.e., an antenna is recently configured to not only receive andtransmit a signal for cellular but also receive a signal of GPS (GlobalPositioning System) or to be used for Blue-tooth antenna for wirelessLAN by a cellular phone. Therefore, signals of two or more frequencybands are likely to be fed to the feeding terminal electrode 84.

On the other hand, formed on the circuit board 86 having the antennawith built-in filter 85 mounted thereon are electronic circuits such asa receiving circuit or transmitting circuit connected to the feeder 862,in which a low noise amplifier not shown is included on the receivingside. In the case where reception and transmission are performed in twoor more frequency bands, these electronic circuits are formed for eachfrequency band. The feeding terminal electrode and these electroniccircuits are electromagnetically coupled, with the result that the noiseor a signal of the other frequency band picked up by the feedingterminal electrode interferes directly with the circuits on the circuitboard, thereby entailing a problem of deteriorating (increasing noise)isolation property (meaning that the coupling between each other issmall) or reducing transmit-receive characteristic.

The present invention is accomplished to solve the aforementionedproblem, and aims to provide an antenna with built-in filter that isdesigned to downsize by integrating a filter, made by laminatingdielectric sheets, and a radiation element, wherein a mutualinterference is not caused between an electronic circuit on a circuitboard and a feeding terminal electrode of the antenna even if theantenna is directly mounted on the circuit board, thereby being capableof enhancing isolation property and improving transmit-receivecharacteristic.

Another object of the present invention is to provide a mountingstructure of an antenna with built-in filter mounted on a circuit boardso as to be suitable for preventing a mutual interference between theantenna and an electronic circuit, when this antenna with built-infilter is mounted on the circuit board.

DISCLOSURE OF THE INVENTION

An antenna with built-in filter according to the present inventionincludes: a laminated dielectric block that is formed such thatdielectric sheets each having a conductive film formed on one surfaceare laminated so as to constitute at least one filter; a radiationelement fixedly provided at the laminated dielectric block andelectrically connected to one electrode of the filter; and a feedingterminal electrode electrically connected to the other electrode of thefilter and provided at the outer face of the laminated dielectric block,wherein the feeding terminal electrode is provided on a mounting facethat is a face opposing to a circuit board when the laminated dielectricblock is mounted on the circuit board and a connecting wiring forconnecting the other electrode of the filter and the feeding terminalelectrode is not exposed to the outer face other than the mounting faceof the laminated dielectric block.

The “radiation element” means here the one that can radiate radio wavesuch as a radiation electrode wherein a radiation pattern is formed, ora plane radiation electrode pattern which are formed on a face of thedielectric block with a conductive film. Moreover, the phrase“electrically connected” includes not only a direct connection with aconductor but also a connection via other electronic device orelectromagnetic coupling even though there is no direct connection witha conductor. Further, the “outer face” means a face exposed to anoutside of the laminated dielectric block, and the “mounting face” meansa face opposing to a circuit board on which the laminated dielectricblock is mounted.

According to this construction, the feeding terminal electrode facesonly to a circuit board on which the antenna with built-in filter ismounted and a multi-layer laminate structure in which a shielding plateis embedded can be used for the circuit board, whereby the feedingterminal electrode can be connected to a feeder of the circuit board asit is perfectly shielded. Consequently, external noise is not directlycarried on the feeding terminal electrode, and even if a signal of otherfrequency band appears on the feeding terminal electrode, it is notcoupled to a receiving circuit of different frequency band. As a result,isolation property between the feeding terminal electrode and theelectronic circuit on the circuit board is extremely enhanced, andfurther, there is no fear of reducing characteristic of a desiredtransmitting or receiving signal, thereby obtaining an extremelyhigh-performance antenna with built-in filter.

The electrical connection between the other electrode of the filter andthe feeding terminal electrode is performed through a via-contact madeof a conductor embedded into a contact hole provided on a dielectricsheet.

The mounting structure of the antenna with built-in filter according tothe present invention comprises; the antenna with built-in filter ofclaim 1 and a circuit board having a laminated structure including atleast a shielding layer and a wiring layer, on which the antenna ismounted, wherein the feeding terminal electrode is electricallyconnected to an internal wiring provided in the circuit board and anelectronic device provided on a surface of the circuit board iselectrically connected to the feeding terminal electrode via theinternal wiring. This structure makes it possible to use the internalwiring for a feeder that is electrically connected to the feedingterminal electrode. Therefore, the feeding terminal electrode can beconnected to a component constituting the electronic circuit with astate that it is not at all exposed to the outside and it is shielded bya shielding plate, thereby being capable of providing a transmitter or areceiver with extremely high performance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1C are explanatory views showing one embodiment of anantenna with built-in filter according to the present invention;

FIGS. 2A and 2B are views showing a constructional example of a filterin a laminated dielectric block shown in FIG. 1;

FIG. 3 is a view showing a constructional example of a via-contact shownin FIG. 1;

FIG. 4 is a sectional explanatory view of an example for mounting theantenna with built-in filter shown in FIG. 1 to a circuit board;

FIG. 5 is a view showing an outline of a device testing a performance ofFIGS. 6A and 6B;

FIG. 6A is a frequency characteristic view of antenna gain according tothe present invention, and FIG. 6B is a frequency characteristic view ofantenna gain according to a conventional structure;

FIGS. 7A and 7B are explanatory views of a state where a conventionalantenna with built-in filter is mounted to a circuit board.

BEST MODE FOR CARRYING OUT THE INVENTION

Subsequently, an antenna with built-in filter according to the presentinvention will be explained with reference to drawings. As FIGS. 1A to1C show a constructional explanatory view according to one embodiment,the antenna with built-in filter of the present invention has alaminated dielectric block 3 wherein dielectric sheets 31 each having aconductive film formed on its one surface are laminated so as toconstitute at least one filter 2. A radiation element 1 is provided soas to fix to the laminating dielectric block 3, wherein one electrodenot shown of the filter 2 is electrically connected to the radiationelement 1. Further, the other electrode 22 of the filter 2 is connectedto a feeding terminal electrode 4 provided at the outer face of thelaminated dielectric block 3 through a via-contact 33 and a wiring 34.The present invention is characterized in that, as shown by a back sideview of FIG. 1C, the feeding terminal electrode 4 is provided only on amounting face B that is a face opposing to a circuit board not shownwhen the laminated dielectric block 3 is mounted on the circuit board,not being exposed to the side face of the laminated dielectric block 3that is exposed to the outside.

Although the example shown in FIG. 1 illustrates only one radiationelement 1 and one filter 2 corresponding to a signal of one frequencyband, plural radiation elements 1 (there may be a case where oneradiation element can be used for plural frequency bands) or filters 2for plural frequency bands may be mounted to or installed in onelaminated dielectric block 3 in order to make it possible to receive ortransmit signals of plural frequency bands such as AMPS/PCS for acellular phone, global positioning system (GPS) or Bluetooth (BT). Inthe case where filters for two or more frequency bands are installedinto one laminated dielectric block 3, vertical shielding walls arepreferably formed in the laminated dielectric block 3 for every block offilter 2 for respective frequency band in order that they are notinterfered with each other. The shielding wall can be formed by the samemethod as that of a band-shaped via-contact described later.

Although the example shown in FIG. 1 illustrates that the radiationelement 1 is formed in a patch-like radiation electrode provided on agrounding conductor 35 via the dielectric layer, other configuration maybe possible such as a ceramic antenna wherein band-like conductor or theradiation electrode that is patterned by the band-like conductor iscapacitively coupled to the feeding electrode, or such configuration ispossible in which the radiation element 1 is provided at the side faceof the dielectric block 3.

An inductor L, capacitor C and resonator are formed in the laminateddielectric block 3 as described later and they are connected as shown inFIG. 2A to form a single filter or a filter group that is a combinationof at least two of a low-pass filter, a high-pass filter, a band passfilter BPF with the resonator and a band-elimination filter, whereby thefilter can be configured to pass only a desired frequency band. Oneelectrode 21 of the filter 2 is electrically connected to the radiationelement 1, while the other electrode 22 is electrically connected to thefeeding terminal electrode 4. Further, in the case where radiationelements and filters for two or more frequency bands are installed for,for example, a cellular phone of AMPS (0.8 GHz)/PCS (1.8 GHz) and forGPS (1.5 GHz), the filter connected to the antenna for GPS has connectedthereto a high-pass filter HPF for cutting a frequency band lower than1.4 GHz and a low-pass filter LPF for cutting a frequency band higherthan 1.6 GHz and has inserted therein a band-elimination filter BEF of1.8 GHz for surely cutting 1.8 GHz-band close to 1.5 GHz, as shown inFIG. 2B, thereby being capable of surely preventing the other signalfrom being interfered. It can be formed by only changing the size orconnection of L and C for the other frequency band.

The laminated dielectric block 3 has ceramic sheets (green sheets) 31each having a conductive film formed on one face in a desired pattern bya printing as shown by a sectional explanatory view in FIG. 1B, whereina conductive film is formed in a desired pattern on each dielectricsheet 31 such that a strip line that constitutes an inductor L, and acapacitor C which is formed by forming the conductive film with thedielectric sheet 31 sandwiched therebetween are formed respectively, andwherein via-contact 32 for connecting the inductor Land the capacitor C,and a via-contact 33 and wiring 34 for connecting the other electrode 22of the filter 2 described later to the feeding terminal electrode 4 areformed. The laminated dielectric block 3 also may have a conductive film35 formed on its entire face for shielding. The ceramic sheets 31 aresuperposed and pressed, whereupon the resultant is cut and sintered toform the laminated dielectric block 3 having an outer size ofapproximately (2 to 30 mm)×(2 to 30 mm) and a thickness of approximately0.5 to 7 mm, for example.

The via-contact 33 and the wiring 34 for connecting the other electrode22 of the filter 2 to the feeding terminal electrode 4 are formed inorder that the other electrode 22 is directly drawn to the bottomsurface (mounting face B) of the laminated dielectric block 3 throughthe inside of the laminated dielectric block 3, that means the otherelectrode 22 is not drawn to the bottom surface through the side face ofthe laminated dielectric block 3. The example shown in FIG. 1illustrates that two via-contacts 33 are connected via the wiring 34.The reason of this is as follows. Specifically, a first reason is in thecase where the electrode 22 of the filter and the feeding terminalelectrode 4 are deviated from the viewpoint of plane. And a secondreason is in the case where the distance between the electrode 22 andthe bottom face of the dielectric block 2 is great, because thepositions where the via-contacts are formed become thick if via-contactsare formed at the same positions of many dielectric sheets. Therefore,two or more via-contacts 33 are formed for shifting each position of thevia-contacts in the case where the via-contacts 33 are required to beshifted at a different position from the viewpoint of plane. However, ifthere is no such need, a single via-contact 33 can connect the otherelectrode 22 of the filter 2 and the feeding terminal electrode 4directly.

The upper and lower conductive films between which the ceramic sheet 31is sandwiched are connected by the via-contacts 32 and 33 that establisha connection by embedding the conductor into a contact hole(though-hole) formed in the ceramic sheet 31. As shown in FIG. 3 by avertical sectional explanatory view of the via-contact section 32 shownin FIG. 1B, the via-contacts 32 and 33 are formed into a band-like(band-form) shape. This increases the cross sectional area of theconnection to prevent the increase in high-frequency resistance andinductance, whereby a high-performance filter can be formed although thefilter has a laminated structure. The band-like via-contacts 32 and 33can be formed by forming the contact hole provided at the ceramic sheet31 into a long and thin (slender) groove.

The laminated dielectric block 3 having the above-mentionedconfiguration is manufactured as follows. A contact hole or slendergroove for the via-contact is formed by a forming die on a ceramic sheet31 having a thickness of about 100 μm, and then, conductor in the groove(via-contact) and required strip line are formed by a printing of aconductive paste. Thereafter, several tens of the ceramic sheets aresuperposed and pressed to be hardened in order that the filter circuitor via-contacts 32 and 33 are formed as described above, and sinteredafter cutting into a size of each laminated dielectric block or ditchingfor cutting, thereby obtaining a laminated dielectric block. A conductorsuch as a silver paste is provided by a printing on its side face,whereby the radiation element 1 or grounding conductor 36 can be formedat the front face, side face or bottom face of the laminated dielectricblock 3.

The feeding terminal electrode 4 is formed by the same manner as formingthe aforementioned radiation element 1 and the grounding conductor 36,wherein a conductive material such as a silver paste is formed by aprinting so as to connect to the via-contact 33, and the resultant issintered.

The antenna with built-in filter as described above is directly mountedto a circuit board on which a signal processing circuit is formed andincorporated into a housing of a cellular phone or the like. The antennawith built-in filter 5 having a configuration such that the feedingterminal electrode 4 of the present invention is not exposed to the sideface of the laminated dielectric block 3 can connect the feedingterminal electrode 4 and a low noise amplifier 65 of a receiving signalprocessing circuit, for example, with a perfect shielding state by usingthe circuit board 6 having a laminated structure wherein at least onewiring layer such as a shielding layer 63 and feeder 62 is formed on aninsulating sheet 61 as shown in FIG. 4 (although in the example shown inFIG. 4, the shielding layer 63 is formed on the upper and lower outerfaces, only one shielding layer may be formed or it may be formedinside). Therefore, the coupling between the feeding terminal electrode4 and the electronic circuit can almost perfectly be eliminated.

Even if the feeding terminal electrode is directly connected to thefeeder on the surface of the circuit board that is a conventionalmounting structure shown in FIG. 7, the mutual coupling between thefeeding terminal electrode and the electronic circuit on the circuitboard is extremely restrained, since the feeding terminal electrode iscompletely positioned only at the back side of the laminated dielectricblock, thereby enhancing isolation property between the feeding terminalelectrode and the electronic circuit on the circuit board.

The antenna with built-in filter according to the present invention isconnected to a feeder provided on a surface of a circuit board to checkfrequency characteristic of the antenna, that is a gain relationship toa frequency, by comparing it to a conventional antenna with built-infilter having a structure wherein a feeding terminal electrode isprovided on a surface of a side wall of the laminated dielectric block.This characteristic test was made as follows. Specifically, as shown inFIG. 5, an antenna 72 for a test was installed to a housing 71 such as,for example, a cellular phone. The circuit board 6 having the antennawith built-in filter 5 mounted thereto was attached in the housing 71. Again-frequency characteristic by a receiving signal was tested when theantenna 72 for a test radiates signals having each frequency of 0.8 to 4GHz. It should be noted that Bluetooth antenna for 2.4 GHz band was usedfor the antenna with built-in filter 5. FIG. 6A shows a characteristicof the structure in which the antenna according to the present inventionis directly connected to the feeder provided on the surface of thecircuit board, while FIG. 6B shows a characteristic of the structure inwhich the feeding terminal electrode is also provided on the side faceas shown in FIG. 7.

As apparent from FIGS. 6A and 6B, a great attenuation is made in afrequency band of not more than 1.76 GHz and not less than 3.04 GHzaccording to the present invention (it is preferable to attenuate in afrequency band other than a desired 2.4 GHz band), while attenuation isvery small even in a separate frequency band according to theconventional structure of FIG. 6B, that means external noise is prone tobe picked up. In the present invention, the filter is incorporated so asto attenuate a signal of a frequency band other than 2.4 GHz band.Therefore, attenuation is made in the frequency band separate from 2.4GHz due to the operation of the filter in the present invention.However, there is radio wave directly picked up by the feeding terminalelectrode in the conventional structure, and it is considered that thisradio wave is prone to be picked up as noise, since this radio wavecannot be eliminated because it does not pass the filter. Specifically,it is indicated that the structure having the feeding terminal electrodeexposed to the outside is greatly susceptible to the external noise andthat mutual interaction is likely to occur between the feeding terminalelectrode and the receiving circuit. This tendency is not limited to theBluetooth antenna, but the same result can be obtained by a GPS antennaor cellular antenna.

According to the present invention, the feeding terminal electrode ofthe antenna with built-in filter is provided only on the mountingsurface that opposes to the circuit board on which the antenna withbuilt-in filter is to be mounted, not provided at the side wall that isexposed to the outside. On the other hand, conductive films are suitablyprovided in a wide range in the laminated dielectric block to functionas a shielding plate, and the grounding conductor can be provided alsoaround the feeding terminal electrode. Further, the function of ashielding plate can also be given to the circuit board. Therefore,interference with the outside can surely be restrained. Consequently,there is no chance that the receiving signal directly enters the feedingterminal electrode without passing through the filter, and further,there is no chance that the feeding terminal electrode and theelectronic circuit on the circuit board are electromagnetically coupledto cause interaction. As a result, the isolation property is extremelyenhanced (that means the degree of coupling is small between the feedingterminal electrode and the neighboring electronic circuit) and theinfluence by the external noise is greatly restrained, thereby beingcapable of enhancing antenna performance.

Further, according to the present invention, the feeding terminalelectrode is not provided at the side face of the laminated dielectricblock 3, so that the electronic circuit formed on the circuit board andthe antenna with built-in filter can be arranged so as to close to eachother, which contributes to downsize the circuit board. Moreover, usingthe circuit board of a laminate structure having a wiring thereinenables an electrical connection with a perfect shielding state betweenthe feeding terminal electrode and the components of the electroniccircuit, thereby being capable of further enhancing the isolationproperty. Further, there arises an effect of increasing a degree offreedom in the arrangement of the components on the circuit boardwithout causing any trouble due to the perfect shielding function, evenif it is connected to a remote electronic component.

According to the present invention, the feeding terminal electrode ofthe antenna with built-in filter wherein the antenna and the filter areintegrated is formed such that it is difficult to interfere with theoutside, thereby being capable of remarkably restraining the interactionbetween the feeding terminal electrode and the circuit board on whichthe antenna with built-in filter is mounted. Therefore, the antenna withbuilt-in filter having remarkably enhanced transmitting or receivingcharacteristic can be obtained. Moreover, the antenna with built-infilter and the electronic circuit on the circuit board can be arrangedso as to close to each other, in addition to the integration of thefilter and the antenna, thereby contributing to the miniaturization evenwhen miniaturization is particularly demanded for a portable device suchas a cellular phone.

Moreover, in the case where the antenna with built-in filter accordingto the present invention is used, the substrate of the laminatedstructure is used for the circuit board and it is connected to theelectronic circuit via the shielded internal wiring, thereby beingcapable of further enhancing isolation property.

INDUSTRIAL APPLICABILITY

According to the present invention, the feeding terminal electrode canbe connected to a feeder of the circuit board as it is perfectlyshielded. Consequently, external noise is not directly carried on thefeeding terminal electrode, and even if a signal of other frequency bandappears on the feeding terminal electrode, it is not coupled to areceiving circuit of different frequency band. As a result, it can beutilized as a compact, high-performance antenna for cellular, GPS orBluetooth suitable to be mounted to a cellular phone or portableterminal device that is used in plural frequency bands.

1. An antenna with built-in filter comprising: a laminated dielectricblock that is formed such that dielectric sheets each having aconductive film formed on one surface are laminated so as to constituteat least one filter; a radiation element fixedly provided at thelaminated dielectric block and electrically connected to one electrodeof the filter; and a feeding terminal electrode that is provided on amounting face of the dielectric block, and opposes to a circuit boardwhen the laminated dielectric block is mounted on the circuit board;wherein the feeding terminal electrode and the other electrode of thefilter are electrically connected by at least one connecting wiringprovided on one of one or more dielectric sheets, and two or morevia-contacts each of which is composed of a conductor embedded into acontact hole formed in at least one of the one or more dielectricsheets, wherein the at least one connecting wiring and the two or morevia-contacts are not exposed to an outer face of the laminateddielectric block, and wherein the two via-contacts are formed at placesthat are different from each other on a plane view of the dielectricblock.
 2. The antenna with built-in filter of claim 1, wherein at leastone of the via-contacts is formed into a band shape by embedding theconductor into a slender and groove-like contact hole provided on the atleast one of the one or more dielectric sheets so as to increase thecross section of the via-contact.
 3. The antenna with built-in filter ofclaim 1, wherein the filter comprises a filter group including at leasttwo of a low-pass filter, a high-pass filter and a band eliminationfilter.
 4. A mounting structure of an antenna with built-in filtercomprising: the antenna with built-in filter of claim 1; and a circuitboard which has a laminated structure including at least a shieldinglayer and a wiring layer, on which the antenna is mounted, wherein thefeeding terminal electrode is electrically connected to an internalwiring provided in the circuit board and an electronic device providedon a surface of the circuit board is electrically connected to thefeeding terminal electrode via the internal wiring.
 5. The antenna withbuilt-in filter of claim 1, wherein the radiation element is formed soas to be capable of receiving or transmitting two or more frequencybands, and two or more filters are formed so as to be capable ofreceiving or transmitting signals of the two or more frequency bands. 6.The antenna with built-in filter of claim 5, wherein one of the two ormore filters comprises a band elimination filter for eliminating afrequency band of a signal that is received or transmitted by the otherfilter of the two or more filters.
 7. The antenna with built-in filterof claim 5, wherein the two or more frequency bands received ortransmitted by the radiation element comprise at least two of frequencybands for cellular, a frequency band for GPS and a frequency band forBluetooth.
 8. The antenna with built-in filter of claim 5, wherein twoor more filters are shielded not so as to interfere with each other byforming a shielding wall in a vertical direction in dielectric sheets ofthe laminated dielectric block, the shielding wall being formed by aband-like via-contact provided in the dielectric sheets.
 9. An antennacomprising: a dielectric filter block having first and second filterelectrodes therein; a radiation element provided on the dielectricfilter block and electrically connected to the first filter electrode ofthe dielectric filter block; a feeding terminal electrode provided on amounting face of the dielectric filter block that faces a circuit boardwhen the dielectric filter block is mounted on the circuit board; atleast one connecting wiring that is provided in the dielectric filterblock and extends in a first direction approximately parallel to themounting face of the dielectric filter block; two or more via-contacts,each of which is composed of a conductor embedded into a contact holeformed in the dielectric filter block and extends in a second directionwhich is different from the first direction, and in which the two ormore via-contacts are electrically connected through the at least oneconnecting wiring; wherein the feeding terminal electrode and the secondelectrode of the dielectric filter block are electrically connected bythe two or more via-contacts and the at least one connecting wiring; andwherein the two via-contacts are formed at different places from eachother in a plane view of the dielectric filter block.
 10. The antennaaccording to claim 9, wherein the dielectric filter block includes aconductive film.
 11. The antenna according to claim 9, wherein thedielectric filter block includes two or more dielectric sheet.